When I build a single page template in Elementor and use the form widget in it, I can display the meta box fields in it without any problems. I can see them in the backend (Elementor Editor) but they are not displayed in the front-end or sent with the form email.
I've created an Elementor Form widget on my demo site, added a new form item, and connect the default value to a custom field value to show on the frontend as well. Screen record https://www.loom.com/share/e990a258b8ac416197a8ea30c8a51ba7
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